Double Setback for Gilead

Gilead Sciences, Inc (GILD) suffered two successive setbacks when the US Food and Drug Administration (:FDA) issued complete response letters (CRLs) to the company’s HIV candidates, elvitegravir and cobicistat, for use as part of HIV therapy regimens.

We note that Gilead is seeking approval of elvitegravir for use in treatment-experienced HIV patients. Cobicistat acts as a “boosting” agent whose addition causes blood levels of protease inhibitors to increase, thereby enabling the HIV therapy to be dosed once daily.

The US regulatory body declined to approve the candidates on the basis of the submitted data due to shortcomings observed in the documentation and validation of certain quality testing methods. Gilead is working with the US regulatory body to address the queries raised in the CRLs.

We note that Gilead had submitted the new drug applications (NDAs) seeking FDA approvals for the candidates in Jun 2012. Both applications were subsequently accepted for review by the FDA. The FDA had assigned target dates of Apr 27 and Apr 28, 2013 for deciding on the NDAs of elvitegravir and cobicistat, respectively.

Even though the US regulatory body declined to approve the HIV candidates in their present forms, the agency did not ask for additional studies to be conducted. This brings in some relief for Gilead as additional studies would have pushed up the research & development costs for the company and delayed the approval even further.

We note that elvitegravir and cobicistat are also components of Gilead’s HIV combination pill Stribild, approved in the US in Aug 2012 as a first-line therapy for treating adults infected with the HIV virus. The other component of the pill is Truvada. The CRLs issued by the FDA regarding elvitegravir and cobicistat individually will not impact Stribild in any way.